Track roller with replaceable and reversible flanges

ABSTRACT

A track roller assembly for crawler-type tractors including a hub adapted to be journalled on a shaft and a pair of rims, one at each end of the hub. Each rim includes an annular tread and at least one radially outwardly extending, annular flange adjacent the tread. The treads and the flanges and the hub are made separate from each other and each flange is symmetrical so that it may be easily removed to be reversed and/or replaced without discarding the associated tread or the hub.

Boggs 1451 Mar. 11, 1975 TRACK ROLLER WITH REPLACEABLE 3,154,958 11/1964 Cadwell et a1. 74/2303 AND REVERSIBLE FLANGES 3,580,093 5/1971 Tomizawa 74/2303 3,773,393 11/1973 Story et a1. 308/18 Inventor: Roger L. Boggs, East Peoria, 111.

Assignee: Caterpillar Tractor Co., Peoria, 111.

Filed: Dec. 12, 1973 Appl. No.: 424,095

U.S. C1 74/2303, 74/2305, 305/14,

References Cited UNITED STATES PATENTS Primary ExaminerSamuel Scott Assistant Examiner AHan R. Burke Attorney, Agent, or Firm-Caterpillar Tractor Co.

[57] ABSTRACT A track roller assembly for crawler-type tractors including a hub adapted to be journalled on a shaft and a pair of rims, one at each end of the hub. Each rim includes an annular tread and at least one radially outwardly extending, annular flange adjacent the tread. The treads and the flanges and the hub are made sepa' rate from each other and each flange is symmetrical so that it may be easily removed to be reversed and/0r replaced without discarding the associated tread or the hub.

5 Claims, 1 Drawing Figure TRACK ROLLER WITH REPLACEABLE AND REVERSIBLE FLANGES BACKGROUND OF THE INVENTION This invention relates to track roller assemblies and, more particularly, to an improved track roller assembly whereby cost of maintenance is minimized.

Pertinent prior art includes US. Pat. Nos. 2,804,358 to Eriksson; 3,154,958 to Caldwell et al; 3,515,446 to Maguire; 3,580,093 to Tomizawa; and 3,586,398 to Dadds.

Crawler-type tractors and, particularly, the tracks thereof, are subject to substantial abuse during use simply due to the hostile environment in which they are intended to operate. As is well known, such tractors are frequently employed in building roads, clearing areas, earth moving and transport of other vehicles in severe terrain. 1

Such operating environments require that the crawler'type tractor undergo multiple turning movements to allow it to be aligned with the work, as rocks or trees, or simply in traversing side hill areas. Such multiple turning movements cause substantial side loading of the track chains with the result that such side loading is inevitably transferred to the drive sprockets, idlers and track rollers.

Customarily, each of such elements have side flanges for guiding the chains and it is to such side flanges that the loads are transferred. As a result of such side load ing as well as the abrasive nature of the typical environment in which such tractors are used, substantial wear on the guide flanges occurs.

The wear problem is compounded by the fact that wear also occurs within the hinge pins and bushing joints of the track chains and as such wear occurs, during use the tracks will snake allowing the chain links to more freely work outwardly and up over the roller flanges to increase the tendency toward premature deterioration.

Typically, the parts of a roller assembly subjected to such wear through contact with the chains include rims at each end of a hub. Each rim, in turn, typically includes a so-called tread" and at least one radially outwardly extending guide flange. Because of the severe operating environments, the rims are made of extremelyhigh quality, and thus expensive, steel. Accordingly, when a rim must be discarded due to wear, the replacement thereof is a substantial expense.

SUMMARY OF THE INVENTION It is the principal object of the invention to provide a new and improved track roller assembly for crawlertype tractors. More specifically, it is an object ofthe invention to provide such a track roller assembly whereby the high cost of replacing worn parts is mini mized.

The exemplary embodiment of the invention achieves the foregoing'objects in a track roller assembly including a hub which is adapted to be journalled on a shaft and which includes a pair of rims, one at each end of the hub. Each rim, in turn, includes a radially outwardly facing, annular tread and at least one radially outwardly extending, annular flange adjacent the tread.

The inventive improvement includes the fabrication ofthe roller assembly such that the hub, the treads, and

' cludes reduced ends 14 each having a flat 16 for non the flanges are all separate parts and by the further fabrication of each flange as a symmetrical disc-like element.

Through the invention, where any one or more of the hub, the treads or the flanges are not worn, while other of those elements are, only the worn elements need be replaced. Moreover, through the fabrication of the flange as a symmetrical element, when the side of the same engaging the track chain becomes worn to the point of requiring replacement, the flange may be removed and reversed and replaced so that the other side of the flange, not yet worn, may be employed to guide the track chains. Thus, replacement costs for parts are minimized.

Other objects and advantages of the invention will become apparent from the following specification taken in conjunction with the accompanying drawing.

DESCRIPTION OF THE DRAWING The FIGURE is a side elevation of a track roller assembly on frame members of a tractor, with parts broken away and shown in section for clarity.

DESCRIPTION OF THE PREFERRED EMBODIMENT An exemplary embodiment of a track roller assembly made according to the invention is illustrated in the FIGURE as being mounted on a shaft, generally desig nated 10, extending between and secured to parallel frame members, generally designated 12, customarily provided on crawler-type tractors. The shaft 10 inrotative engagement with the underside of the associated frame member 12. Mounting collars 18 secure the shaft 10 in place by means of bolts 20, as is well known.

A conventional keying means 22 is employed to prevent lateral shifting of the shaft 10 relative to the collar 18.

The shaft 10 includes an enlarged center 24 which journals the roller assembly as will be seen. The enlarged center 24 may include a pocket 26 for receipt of a lubricant, as is well known in the art.

The roller assembly includes a metal hub 28 which is journalled on the shaft 10 for rotation thereabout by means of a sleeve-like bearing 30. At each end of the hub 28 is a rim, generally designated 32, which is pressfit on the hub 28 into abutment with a respective annu lar, radially outwardly extending, positioning flange 34. Each rim 32 includes one annular, radially outwardly facing tread 36 and at least one annular, radially outwardly extending, guide flange 38. In the preferred embodiment, an additional guide flange 40 is provided for each tread 36 although the presence or absence of the guide flange 40 will depend upon the specific form of track with which the track roller assembly is intended to be used.

Each of the treads 36 consists of a relatively thick, selectively hardened, annular metal ring with the axially outer portions being case hardened to a substantial depth, typically on the order of 3/16 of an inch. The axially inner portions are tempered to provide maximum strength.

The flanges 38 are configured as a symmetrical disclike element formed of metal. Each includes a beveled surface 41 on one face and a beveled surface 42 on the opposite face, the beveling being at the periphery of each disc-like element. As the flange 38 is intended to be symmetrical, the beveling 41 is identical to the beveling 42.

Each disc 38 includes a central opening 44 and ex- 7 tending inwardly within the opening 44 is a radially inwardly extending retaining flange 46. The location of the flange 46 is such as not to disturb the symmetry of the flange 38.

The retaining flanges 46 are adapted to abut respective ends of the hub 28 for positioning purposes and the flanges 38 are, in turn, held in such a relationship by retaining plates 48. The retaining plates 48 are secured to the hub 28 by means of bolts 50 received in tapped bores 52 within the hub 28. Each of the retaining plates 48 mounts a thrust bearing 54 which is adapted to engage the enlarged center 24 of the shaft 10.

Finally, conventional seals 60 are interposed between the retaining plates 48 and the mounting collars 18 so as to preclude the flow of lubricant outwardly from the interior of the assemblage.

Turning now to the flanges 40, each, like the flanges 38,is formed of a disc-like element having a central opening 62 by which the same may be press-fit onto the hubinto abutment with the retaining flange 34. Also, each flange 40 has'beveled surfaces 64 at its periphery on opposite faces thereof and the beveled surfaces 64 are such that each of the flanges 40 is symmetrical. As illustrated, the two flanges 40 are identical to each other as are the flanges 38.

From the foregoing, it will be recognized that whenever there is sufficient deterioration due to wear to require the replacement of any one of the three basic elements,.i.e., the hub 28, a tread 36, or one of the flanges 38 or 40, unworn ones of such elements need not be discarded by reason of their construction separate from the others allowing their replaceability. Quite importantly, the symmetric construction of the flanges 38 or 40 allows the same to be reversed when one face thereof has deteriorated due to wear to the point where it is no longer suitable. Such an operation can easily be accomplished with the use of a pulling tool after first removing the retaining brackets 18 and the retaining plates 48. As a result, high quality metal parts not requiring replacement need not be replaced when other companion parts must be.

Moreover, it will be appreciated that the flanges 38 and 40; can be made with different metallurgical compositions than the treads 36 so as to allow them to withstand high impact loads without deforming or cracking more successfully than would be the case if they were integral with or formed of the same composition as the treads. The unique construction allows the flanges to be case hardened on both sides to an appropriate depth as, for example, /8 of an inch, and yet have a tempered core sufficiently thick to insure adequate strength.

lmportantly, the fact that the guide flanges are separate from the roller tread allows them to retain a relatively fixed disposition radially on the hub to thereby prevent the tendency of the hub to bell-mouth under high impact loads as such loads are absorbed and the rimsbecome diametrically enlarged.

Finally, servicing or rebuilding of a roller assembly made according to the invention can be accomplished much more quickly and efficiently than can the same operations be performed with those type of track roller assemblieswherein hard face welding is employed.

I claim:

1. In a track roller assembly including a hub adapted to be journalled on a shaft and a pair of rims, one at each end of the hub and each including a radially outwardly facing annular tread and atleast one radially outwardly extending annular flange adjacent the tread, the improvement wherein each of said hub, said treads and said flanges are separate parts and wherein each flange is a symmetrical disc-like element whereby, after use and attendant wear, a flange may be removed to be reversed and/or replaced without discarding the associated tread and/or the hub.

2. The track roller assembly of claim 1 wherein two said flanges are provided for each tread, said tread being sandwiched by the associated flanges, all said flanges being separate from said treads and said hub, each said flange being a symmetrical, disc-like element.

3. The track roller assembly of claim 1 wherein said flanges have opposed faces, each face being beveled at the periphery thereof, the bevel on one face being symmetrical to the bevel on the other face of the same flange.

4. In a track roller assembly including a hub adapted to be journalled on a shaft and a pair of rims, one at each end of the hub and each including a radially outwardly facing annular tread and at least one radially outwardly extending annular flange adjacent the tread, the improvement wherein each of said treads and said flanges is a separate element and each of said flanges is a symmetrical disc-like element whereby, after use and attendant wear, a flange may be removed to be re versed and/or replaced without discarding the associated tread.

5. A track roller assembly comprising: a hub adapted to be journalled on a shaft, said hub including radially outwardly extending retaining flanges near the ends thereof; a pair of rims, one received on each end of said hub, each including a radially outwardly facing annular tread separate from said hub, each further including a pair of radially outwardly extending annular guide flanges, the guide flanges in each pair sandwiching the associated tread, one of said guide flanges in each pair being in abutment with an associated one of said retaining flanges, each of said guide flanges being a symmetrical disc-like element whereby the same may be reversed after wear on one surface thereof to provide a new surface; and means holding said hub and said rims in assembled relation. 

1. In a track roller assembly including a hub adapted to be journalled on a shaft and a pair of rims, one at each end of the hub and each including a radially outwardly facing annular tread and at least one radially outwardly extending annular flange adjacent the tread, the improvement wherein each of said hub, said treads and said flanges are separate parts and wherein each flange is a symmetrical disc-like element whereby, after use and attendant wear, a flange may be removed to be reversed and/or replaced without discarding the associated tread and/or the hub.
 1. In a track roller assembly including a hub adapted to be journalled on a shaft and a pair of rims, one at each end of the hub and each including a radially outwardly facing annular tread and at least one radially outwardly extending annular flange adjacent the tread, the improvement wherein each of said hub, said treads and said flanges are separate parts and wherein each flange is a symmetrical disc-like element whereby, after use and attendant wear, a flange may be removed to be reversed and/or replaced without discarding the associated tread and/or the hub.
 2. The track roller assembly of claim 1 wherein two said flanges are provided for each tread, said tread being sandwiched by the associated flanges, all said flanges being separate from said treads and said hub, each said flange being a symmetrical, disc-like element.
 3. The track roller assembly of claim 1 wherein said flanges have opposed faces, each face being beveled at the periphery thereof, the bevel on one face being symmetrical to the bevel on the other face of the same flange.
 4. In a track roller assembly including a hub adapted to be journalled on a shaft and a pair Of rims, one at each end of the hub and each including a radially outwardly facing annular tread and at least one radially outwardly extending annular flange adjacent the tread, the improvement wherein each of said treads and said flanges is a separate element and each of said flanges is a symmetrical disc-like element whereby, after use and attendant wear, a flange may be removed to be reversed and/or replaced without discarding the associated tread. 